<template>
  <div id="app">
    <div class="todo-container">
      <div class="todo-wrap">
        <!--自定义事件-->
        <TodoHeader @addTodo='addTodo'/>
        <TodoList 
          :todolist='todolist' 
        />
        <TodoFooter 
          :todolist='todolist' 
          @checkAllTodo='checkAllTodo'
          @clearAllTodo='clearAllTodo'
        />
      </div>
    </div>
  </div>
</template>

<script>
  import pubsub from 'pubsub-js'//消息订阅，pubsub库
  import TodoFooter from "./components/TodoFooter.vue";
  import TodoHeader from "./components/TodoHeader.vue";
  import TodoList from "./components/TodoList.vue";

  export default {
    name: "App",
    components: {
      TodoFooter,
      TodoHeader,
      TodoList,
    },
    data() {
      return {
        todolist:JSON.parse(localStorage.getItem('todolist')) || []
      }
    },
    methods: {
      //添加一个todo
      addTodo(x){
        this.todolist.unshift(x)
      },
      //勾选/取消勾选一个todo
      checkTodo(id){
        this.todolist.forEach((todo)=>{
          if(todo.id === id) todo.done = !todo.done
        })
      },
      //更新todo
      updateTodo(id,title){
        this.todolist.forEach((todo)=>{
          if(todo.id === id) todo.title = title
        })
      },
      //删除一个todo
      deleteTodo(_,id){//pubsub.subscribe接受两个参数(name，id)
        this.todolist = this.todolist.filter(todo => todo.id !== id)
      },
      //全选or全不选
      checkAllTodo(done){
        this.todolist.forEach((todo)=>{
          todo.done = done
        })
      },
      //清除已经完成的所有todo
      clearAllTodo(){
        this.todolist = this.todolist.filter((todo)=>{
          return !todo.done
        })
      }
    },
    watch:{
      todolist:{
        //添加本地存储
        deep:true,
        handler(value){
          localStorage.setItem('todolist',JSON.stringify(value))
        }
      }
    },
    mounted(){
      this.$bus.$on('checkTodo',this.checkTodo)
      this.$bus.$on('updateTodo',this.updateTodo)
      this.pubId = pubsub.subscribe('deleteTodo',this.deleteTodo)
    },
    beforeDestroy(){
      this.$bus.$off('checkTodo')
      this.$bus.$off('updateTodo')
      pubsub.unsubscribe(this.pubId)
    }
  };
</script>

<style>
  /*base*/
  body {
    background: #fff;
  }
  .btn {
    display: inline-block;
    padding: 4px 12px;
    margin-bottom: 0;
    font-size: 14px;
    line-height: 20px;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2),
      0 1px 2px rgba(0, 0, 0, 0.05);
    border-radius: 4px;
  }
  .btn-edit {
    color: #fff;
    background-color: skyblue;
    border: 1px solid rgb(102, 196, 233);
  }
  .btn-edit:hover {
    color: #fff;
    background-color: rgb(64, 180, 226);
  }
  .btn-danger {
    color: #fff;
    background-color: #da4f49;
    border: 1px solid #bd362f;
  }
  .btn-danger:hover {
    color: #fff;
    background-color: #bd362f;
  }
  .btn:focus {
    outline: none;
  }
  .todo-container {
    width: 600px;
    margin: 0 auto;
  }
  .todo-container .todo-wrap {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
  }
</style>
